If water is contaminated after a disaster, there are several ways to purify it.
If you are uncertain about the quality of drinking water, be cautious and purify to be safe even if it looks clean and clear. This will help avoid diarrhoea, or worse, a serious infection.
THE BEST OPTIONS ARE:
Boiling: Boil all drinking water for at least three minutes at a rolling boil to kill off pathogens that could cause serious illness
Bleach: Not all bleaches are created equal. To purify water safely, you need a regular, full strength, unscented bleach containing at least 4% sodium hypochlorite – about 70ml or 1/3 of a cup to 1000 litres of water. Stir well and let stand for at least 30 minutes – the water should keep a slight chlorine taste. If it doesn’t, dose it again as above, stir, and leave it for another 15 minutes.
Purification tablets: These use iodine to purify water and are found in supermarkets, pharmacies, camping and sports stores. Follow the direction on the pack and only use in case of emergency.
Iodine: If it’s an emergency and there are no other choices, use the iodine liquid from the first aid kit. Use 2% USP-strength iodine, adding five drops per litre to clear water and 10 drops per litre to cloudy water. Mix well, then leave 30 minutes. Iodine is poisonous, so be careful if this is your last option and measure carefully.
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This article first appeared in NZ Lifestyle Block Magazine.
FAQs
Bring water to a rolling boil for at least one minute. At altitudes above 5,000 feet (1,000 meters), boil water for three minutes. Let water cool naturally and store it in clean containers with covers.
What is the best way to sterilize water? ›
Boil. If you don't have safe bottled water, you should boil your water to make it safe to drink. Boiling is the surest method to kill disease-causing germs, including viruses, bacteria, and parasites. adding a pinch of salt for each quart or liter of boiled water.
What is the most reliable way to sanitize water? ›
Boiling is the surest method to kill disease-causing organisms, including viruses, bacteria, and parasites. Bring water to a full rolling boil for 1 minute (at elevations above 6,500 feet, boil for 3 minutes), then allow it to cool before use.
What can be used to disinfect water? ›
The U.S. Environmental Protection Agency (EPA) allows drinking water treatment plants to use chloramine and chlorine to disinfect drinking water. Research shows that chloramine and chlorine both have benefits and drawbacks. Chlorine is a highly effective method of disinfection.
What are the 3 methods for disinfecting drinking water? ›
Water disinfection methods that can be applied in the field include use of heat, clarification, filtration, chemical disinfection, and ultraviolet radiation (UVR). Several of these methods are scalable, and some can be improvised from local resources, allowing adaptation to disaster relief and refugee situations.
Which is the best method for sterilization of water? ›
Boiling is a very simple method of water disinfection. Heating water to a high temperature, 100°C, kills most of the pathogenic organisms, particularly viruses and bacteria causing waterborne diseases. In order for boiling to be most effective, the water must boil for at least 20 minutes.
Does boiling water really sterilize it? ›
Boiling water kills or inactivates viruses, bacteria, protozoa and other pathogens by using heat to damage structural components and disrupt essential life processes (e.g. denature proteins). Boiling is not sterilization and is more accurately characterized as pasteurization.
What kills bacteria in water? ›
Boil water, if you do not have bottled water. Boiling is sufficient to kill pathogenic bacteria, viruses and protozoa (WHO, 2015). If water is cloudy, let it settle and filter it through a clean cloth, paperboiling water towel, or coffee filter. Bring water to a rolling boil for at least one minute.
How do you get rid of germs in water? ›
The most common method for how to remove bacteria from water is through the use of chlorine; in fact, about 98% of public water systems use some form of chlorine for disinfection. Chlorine is frequently used because it is inexpensive and effective.
Does boiling tap water purify it? ›
Boiling water can only remove solids and bacteria, meaning it will not remove harmful substances such as chlorine and lead from tap water. Furthermore, boiling tap water with lead actually concentrates this contaminant making it more dangerous than if left alone.
Here are three ways to purify:
- Boiling. Bring the water to a rolling boil for 3-5 minutes. Let cool before drinking.
- Disinfect. You can use household liquid bleach (regular household bleach contains 5.25% sodium hypochlorite) to kill microorganisms. ...
- Distillation. Fill a pot halfway with water.
Mixing hydrogen peroxide products to obtain a solution with a 25 to 50 ppm residual H2O2 in the drinking water required a stock solution of at least 2 oz/gal with most products. However, since hydrogen peroxide products can rapidly lose potency, it is recommended that fresh stock solutions be made every 2 to 3 days.
What are two methods to clean water so it is safe for drinking? ›
Make Your Water Safe by:
- Boiling. If water is cloudy, allow to settle, then skim the clean water above the sediment. ...
- Disinfect by using: Unscented household chlorine bleach or iodine (useful against most, but not all, harmful viruses or bacteria. ...
- Filtering.
Therefore, experts recommend reverse osmosis or deionization for the treatment of water used in all sterilization efforts.
This article first appeared in NZ Lifestyle Block Magazine.